Question

A sample of aluminium nitrate Al(NO3)3 has a mass of 30.5g. What is the total number of atoms in the sample?

Answer 1

Answer:

9 atoms of oxygen, 3 nitrogen atoms, and 1 aluminum atom. I have gone on before that the mole (

N

A

, Avogadro's number) is simply a much larger number, i.e.

N

A

=

6.022

×

10

23

.

So, in 1 mole of

A

l

(

N

O

3

)

3

there are

(

9

×

N

A

)

O

atoms precisely. What is the mass of 1 mol

A

l

(

N

O

3

)

3

?

Explanation:

$9 atoms of oxygen, 3 nitrogen atoms, and 1 aluminum atom. I have gone on before that the mole (NA, Avogadro's number) is simply a much larger number, i.e. NA = 6.022×1023.</p><p></p><p>So, in 1 mole of Al(NO3)3 there are (9 × NA) O atoms precisely. What is the mass of 1 mol Al(NO3)3?</p><p></p><p>$